The invention relates generally to the field of computer aided design and geographic information systems, and in particular to a method of converting a computer aided design of a large scale project to a virtual reality based model.
Computer aided design (CAD) applications are used for both small and large scale products. For small scale projects, typically all the surfaces, shapes and interactions are defined by the user, and the application may generate a detailed 3 dimensional (3D) model which is viewable from any angle. The ability to view the model from any angle, effectively interacting with the model, is a key component in a virtual reality system.
A geographic information system (GIS) is a system for creating, storing, analyzing and managing spatial data and their associated attributes. Preferably a GIS is embodied in a computer system capable of integrating, storing, editing, analyzing, sharing, and displaying geographically-referenced information. In a typical embodiment a GIS is a tool that allows users to create interactive queries, analyze the spatial information, and edit data.
LandXML is an extensible markup language data file format containing civil engineering design and survey measurement data commonly used in the land development and civil engineering industries. LandXML files thus comprise a data format uniquely suited to large scale projects. LandXML is rapidly becoming the file format of choice for sharing and archiving of land design data.
Commercially, large scale projects on the order of civil engineering or land surveying projects have been accomplished with GIS systems. CAD applications have also been developed for use with these large scale projects, primarily due to their ease of use in developing and modifying precise drawings and maps. CAD and GIS visualization applications may provide photo-realistic results using techniques such as ray tracing, radiosity, global illumination and other shading, shadowing and light reflection techniques. Unfortunately, in large scale projects, and in particular those having GIS based data, these techniques are computationally intensive, and thus the photo-realistic results are viewable as a single raster image or stored as a series of raster images compiled in a time ordered sequence which may be viewed as a single animated playback. The computational intensiveness of the prior art thus does not allow for interaction with the model of large scale projects.
Civil engineering and land surveying projects would thus be greatly enhanced by an ability to evaluate large scale designs in a virtual reality environment. There is thus a long felt need for a method and apparatus linking CAD and GIS data to a virtual reality simulator system.